Abstract
Importance
Trimming perforation margins (TFMs) is a classic procedure of myringoplasty.
Objective
The objective of this study was to evaluate the long-term graft outcomes and iatrogenic cholesteatoma of endoscopic cartilage myringoplasty with preserving perforation margins (PFMs) for repairing small- to medium-size perforation.
Study design
Prospective semi-randomly control study.
Setting
Tertiary university hospital.
Participants
Patients with chronic small- to medium-size perforations.
Intervention
TFM group or the PFM group.
Main outcome measures
Comprehensive evaluations included graft success rate, hearing improvement, and imaging examinations at 3, 6, and 36 months after surgery and complications.
Results
At postoperative 3 months, the graft success rate was 91.84% in the TFM group and 96.30% in the PFM group (P = .59). At postoperative 6 months, graft separation resulted in re-perforation in 3.70% patients in the PFM group, and the graft success rate was 91.84% in the TFM group and 92.59% in the PFM group (P = .82). At postoperative 3 years, the graft success rate was 93.88% in the TFM group and 94.44% in the PFM group (P = .77). Although postoperative air bone gaps (ABGs) were not significantly different between 2 groups, the PFM group had better hearing restoration compared with the TFM group in postoperative 3 months or 3 years. Additionally, although no significant differences were found in the ABGs between postoperative 3 months and postoperative 3 years in any group, postoperative 3 years showed better hearing restoration compared with postoperative 3 months. In addition, endoscopic morphology showed the graft stratification in .00% in the TFM group and 11.11% in the PFM group (P = .05). Postoperative high-resolution computed tomography (HRCT) revealed a few soft tissue shadow in 8.16% patients in the TFM group and in 5.56% patients in the PFM group (P = .89); middle ear cholesteatoma was excluded by magnetic resonance imaging. However, HRCT revealed that the middle ear and mastoid were well pneumatized in the remaining patients.
Conclusions and relevance
The long-term graft success rate and hearing improvement of cartilage underlay myringoplasty with PFMs are reliable for repairing small- to medium-size perforations; 3 years imaging examinations did not reveal iatrogenic cholesteatoma. However, it may cause graft stratification and graft separation.
Key Message
* Preserving perforation margins did not affect long-term graft success rate and hearing improvement.
* Three-year imaging examinations demonstrated that no trimming induced iatrogenic cholesteatoma.
* Preserving the perforation margins may cause graft stratification and graft separation.
Introduction
Recent and previous studies have demonstrated that graft reconstruction of chronic perforation experiences graft inosculation, graft neovascularization, and graft epithelization to achieve perforation closure.1 -3 Trimming perforation margins (TFMs) is a classic procedure of myringoplasty in literature and textbook; the traditional ideas consider that the margin tissues could inhibit graft inosculation and graft neovascularization.4,5 In addition, inward epithelium induced iatrogenic cholesteatoma.4,5 Recently, Lou et al6,7 first proposed myringoplasty without TFMs; they found that preserving the margin tissue did not affect the short-term graft outcomes. The advantages of preserving the margins were: (1) shortening the operation time and (2) increasing the contact area between the graft and the tympanic membrane (TM) remnant.6,7 Trimming the margins increased the size of perforations, which converted central perforations into marginal perforations, thereby increasing the risk of graft failure.8,9 However, Lou et al’s6,7 studies were only 6 to 12 months follow-up and the absence of imaging examination. To date, it is unclear whether preserving perforation margins (PFMs) affects the long-term outcomes and induces iatrogenic cholesteatoma. Some scholars suggested that iatrogenic cholesteatoma usually occurred 2 to 3 years after surgery.10,11 This study was the first to perform the imaging examination at 3 years after myringoplasty with PFMs. The objective of this study was to evaluate the long-term graft outcomes and iatrogenic cholesteatoma of endoscopic cartilage-perichondrium underlay myringoplasty with PFMs for repairing small- to medium-size central perforation.
Materials and Methods
Ethical Considerations
The study protocol was reviewed and approved by the Institutional Ethical Review Board of Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, China. Informed consent was obtained from all participants.
Patient Selection
Consecutive adult patients diagnosed with chronic large perforation were enrolled. Inclusion criteria were age > 18 years; unilateral chronic perforation; at least 1 mm of remnant TM around the margins, which is not involved the ossicular chain; a perforation size of ¼ − ½ of the pars tensa area; dry ear for at least 3 months; patients had job and residence stabilization but don’t stay away for long; positive Valsalva maneuver; and an air bone gap (ABG) < 35 dB. The exclusion criteria were revision cases, cholesteatoma, visible ossicular chain abnormality, and fungal otitis externa.
The following data were recorded: age, sex, side, duration, myringosclerosis, smoking status, Valsalva maneuver, and diabetes. Prior to enrollment, temporal bone high-resolution computed tomography (HRCT) was performed, and audiograms were recorded; if the HRCT revealed soft tissue shadow in the mastoids or middle ear, magnetic resonance imaging (MRI) was performed. A Valsalva maneuver was performed before surgery to preliminarily evaluate Eustachian tube function. The patient was asked to perform 5 consecutive Valsalva maneuvers (forcible expiration against closed mouth and nose), it was considered as strong positive if the patient feels a sense of air leakage or “snap” sound in the ear following one to twice consecutive maneuvers; otherwise, it was considered as weak positive following 3 to 5 consecutive maneuvers. Audiometric data were assessed preoperatively and at 3 and 36 months postoperatively based on the standards of the Hearing Committee of the American Academy of Otolaryngology–Head and Neck Surgery. 12
Patient Treatment Allocation and Masking
Consecutive patients who met the inclusion criteria were allocated to either TFM group or PFM group according to the order of submission of written informed consent (thus semi-randomly). The TFM group involves trimming the perforation margins, while the PFM group does not. All the patients underwent endoscopic cartilage underlay myringoplasty without raising a tympanomeatal flap by the same surgeon. The patients and the individual performing the assessment were blinded to treatment allocation.
Surgical Approach
The surgical technique has been described by Lou et al.6,7 All patients underwent endoscopic cartilage underlay myringoplasty without raising a tympanomeatal flap by 0° and 30° rigid endoscope under total intravenous anesthesia. The perforation margins were trimmed in the TFM group, while the PFM group does not; the other procedures are the same in both groups. Additionally, the underside of the TM remnant or middle ear was examined to confirm the presence or absence of ingrowth of epithelium in the PFM group; however, the undersurface of the TM remnant was not scraped with a round knife in the PFM group, and just cartilage perichondrium grafts were inserted during the surgical procedure.
Tragal cartilage with a single-layer perichondrium composite graft was harvested. The lateral perichondrium was raised circumferentially from the cartilage graft, with attachment of the cartilage. The cartilage was shaped based on the size but was more than the trimming perforation (TFM group) or original perforation (PFM group). The perichondrium was trimmed such that it was 1 to 2 mm wider than the cartilage graft.
The cartilage-perichondrium graft was placed trans-perforation, the cartilage graft was placed medial to the TM remnant and annulus, and the perichondrium was also placed medial to the TM remnant and annulus but lateral to the cartilage graft. Both sides of the graft are supported by biodegradable synthetic polyurethane foam (Biodegradable NasoPore, Stryker Canada, Hamilton, ON, Canada) in both groups (Figure 1).

PFM technique. (A) Preoperative perforation. (B) Middle ear packing. (C) The graft placement. (D) Postoperative 42 months.
Postoperative Follow-up
Patients were discharged on the day after surgery. Endoscopic examinations were performed in the outpatient clinic 2 and 4 weeks and 3, 6, and 36 months after surgery. Audiometric evaluations were performed 3 and 36 months after surgery. HRCT was performed 36 months after surgery. If the HRCT revealed soft tissue shadow in the middle ear or mastoids, MRI was performed to exclude cholesteatoma. The individual performing the assessment was blinded to the treatment arm. Graft success was defined as intact TM at each follow-up visit. Graft stratification was defined as, although the TM was intact, the graft was not on the same plane as the TM remnant (Figure 2). Graft separation was defined as an adequate graft size, but the graft did not fuse with the TM remnant (annulus) by endoscope.

PFM technique. (A) Preoperative perforation. (B) Postoperative 45 months. Green arrows indicate the cartilage graft, and red arrows indicate the TM remnant.
Statistical Analyses
Data were expressed as means (with standard deviations) for quantitative variables and as frequencies (with percentages) for qualitative variables. Between-group comparisons were performed using the independent-sample t-test for quantitative variables and the Chi-square test for qualitative variables. The paired t-test was used to evaluate the differences in ABGs or AC or BC thresholds. All statistical analyses were performed using SPSS, version 20 (IBM, Armonk, NY, USA). P < .05 was considered statistically significant.
Results
Demographic Characteristics
In total, 117 patients with unilateral perforations met the inclusion criteria and underwent the surgery; 9 patients lost follow-up in the TFM group, while 5 patients in the PFM group. Finally, 103 patients were included in this study.
Of the 103 ears, 49 were included in the TFM group, and 54 in the PFM group. Demographic data are shown in Table 1. Demographic data were matched between the groups. Central perforations intraoperatively changed into marginal perforations in 26.53% of the TFM group patients and 3.70% of the PFM group patients (P = .00). No ingrowth of epithelium was observed in the both groups.
Select Characteristics of Patient Sample.
Abbreviations: F, female; L, left; M, male; N, no; PFM, preserving perforation margin; R, right; TFM, trimming perforation margin; Y, yes.
Chi-square test.
Independent samples test.
Graft Success Rate
The graft success rate is shown in Table 2. At postoperative 3 months, residual perforation was found in 8.16% (4/49) in the TFM group and in 3.70% (2/54) in the PFM group. Of the 4 patients with residual perforation in the TFM group, 3 patients resulted from inadequate size of graft and 1 patient resulted from postoperative infection. Both the 2 residual perforations resulted from postoperative infection in the PFM. The graft success rate was 91.84% in the TFM group and 96.30% in the PFM group (P = .59).
The Graft Success Rate and Complications in Both Groups.
Abbreviations: HRCT, high-resolution computed tomography; PFM, preserving perforation margin; TFM, trimming perforation margin.
At postoperative 6 months, the number of residual perforation had no change in both groups; however, re-perforation was .00% in the TFM group and 3.70% in the PFM group. The graft success rate was 91.84% in the TFM group and 92.59% in the PFM group; the difference was not significant (P = .82). The re-perforation was due to graft separation in the anteroinferior annulus in the PFM group.
At postoperative 3 years, residual perforation spontaneously healed in 2 patients in the TFM group and in 1 patient in the PFM group; therefore, residual perforation was 4.08% in the TFM group and 1.85% in the PFM group. However, re-perforation was seen in 2.04% in the TFM group, which occurred in the anterosuperior annulus because of inadequate size of cartilage graft. Nevertheless, re-perforation had no change (3.70%) in the PFM group (Figure 3). The graft success rate was 93.88% in the TFM group and 94.44% in the PFM group; the difference was not significant (P = .77).

PFM technique. (A) Preoperative perforation. (B) Postoperative 3 months. (C) 12 months. Red arrows indicate the re-perforation.
Audiologic Outcomes
Preoperative and postoperative audiograms were obtained in all patients in this study. A comparison between the preoperative and postoperative four-tone pure-tone averages (PTAs) for air conduction (AC) and bone conduction (BC) is detailed in Table 3. There were no significant differences between the groups in preoperative AC PTAs, BC PTAs, or ABGs and postoperative AC PTAs, BC PTAs, or ABGs through the surgery. However, postoperative ABG is better than preoperative ABG in any group. In addition, although postoperative ABGs were not significantly different between 2 groups, the PFM group had better hearing restoration compared with the TFM group in postoperative 3 months (the mean ABG improved by 12.21 ± 4.85 dB and 10.21 ± 2.44 dB) or 3 years (the mean ABG improved by 16.49 ± 3.17 dB and 12.58 ± 3.11 dB). Additionally, although no significant difference was found in the ABGs between postoperative 3 months and postoperative 3 years in any group, postoperative 3 years showed better hearing restoration compared with postoperative 3 months.
Preoperative and Postoperative Audiometric Characteristics of Patient Sample.
Paired t-test. P-value: Comparison between 2 groups in terms of gain, pre- or postoperatively.
Abbreviations: ABG, air-bone gap; AC, air conduction; BC, bone conduction; dB, decible; PTA, pure tone average.
Postoperative Complications
No deteriorative sensorineural hearing loss, vertigo, or tinnitus was observed in both groups during the follow-up period. No patients exhibited significant graft lateralization, graft medialization, and graft cholesteatoma.
Endoscopic morphology showed graft stratification in .00% in the TFM group and 11.11% in the PFM group; the difference was significant (P = .05). Postoperative HRCT revealed a few soft tissue shadow in 8.16% patients in the TFM group and in 5.56% patients in the PFM group (P = .89); middle ear cholesteatoma was excluded by MRI. However, HRCT revealed that the middle ear and mastoid were well pneumatized in the remaining patients (Figure 4).

Imaging examination following PFM technique. Preoperative CT (A and B). Postoperative CT (C and D).
Discussion
In the classic textbooks and literature, all the graft techniques required TFMs; their purpose is to improve graft healing and avoid iatrogenic cholesteatoma.13,14 Recently, Lou et al6,7 reported that preserving the perforation margins did not affect the short-term graft outcomes. However, the follow-up was only 6 to 12 months.6,7 Therefore, it is difficult to accurately assess long-term outcomes and iatrogenic cholesteatoma.
The traditional viewpoint believed that the failure of closure in chronic perforation was due to inward migration of the epithelial layer at the perforation margins into the middle ear, which wrapped the fibrous and mucosal layers.5,15 No TFMs would result in the failure inosculation of graft and TM remnant, thereby affecting the graft success.5,15 However, 96.30% of the patients achieved the complete inosculation of graft in the PFM group in this study. Although an adequate cartilage graft was found in 2 cases in the PFM group, endoscopic examination showed that the topical graft was separated from the annulus; these findings suggested failure inosculation of topical graft. Previous clinical studies showed that graft healing following myringoplasty was mainly due to the inosculation of graft and fibrous layer or mucosal layer of the TM remnant. Graft neovascularization and subsequent graft epithelialization were achieved by relying on the blood supply resulting from the fibrous layer of the TM remnant and the graft’s itself.1 -3,16 We speculated that local failure inosculation was due to mucosal epithelialization, resulting in failure or incomplete inosculation. In the early postoperative period, the graft was closely in contact with the mucosal layer because of biomaterial support, while the biomaterial material was completely absorbed over time, resulting in the separation of the cartilage graft from the annulus. Therefore, scraping the mucosal layer of the annulus is recommended to increase the inosculation of the graft and the annulus in patients with an insufficient TM remnant. Another possible reason is the rejection reaction of graft by the local mucosa. However, the exact mechanism of the separation of the cartilage graft from the annulus was unclear.
This study agreed with Lou et al’s6,7 studies; no TFMs did not affect the short-term graft success rate. However, the present study further confirmed that the graft success rates were similar and stable between 2 groups; no TFMs affected the 3-year graft success rate. Previous studies suggested that the graft failure was related to the postoperative infection, insufficient graft size, postoperative graft movement, and unrecognized middle ear mucosal disease. 7 Instead, TFMs increased the chance of marginal perforation. In this study, 26.53% patients developed the marginal perforations in the TFM group. Lou et al 7 reported that the central perforation changed into the marginal perforations in 31.1% patients following trimming margins. Marginal perforation was mainly due to tear of the TM remnant during cartilage placement in 2 patients in the PFM group. Some scholars reported that cartilage push-through can lead to tear of the TM remnant.17,18 It is well known that marginal perforations increased the possibility of graft failure.8,13,14 Although the graft success rate was not significantly different between the 2 groups, 3/4 residual perforations could not have close contact with the perforation margins due to insufficient graft size in the TFM group, and only 1 was due to the postoperative infection. Nevertheless, both 2 cases with residual perforation were due to postoperative infection in the PFM group. Additionally, 1 re-perforation was due to the defect of the cartilage graft in the TFM group. The possible reason was that the perichondrium graft has too little contact with the annulus due to insufficient cartilage graft size, and the cartilage is pulled along with the vibration of the ossicular chain, resulting in the perichondrium graft separating from the TM remnant. However, both the 2 re-perforations in the PFM group were due to local failure graft inosculation.
Another key assessment is iatrogenic cholesteatoma. The epithelium of the perforation margins easily migrated inwardly into the middle ear and theoretically induced the iatrogenic cholesteatoma.4,5,15 However, in this study, 3-year imaging examination showed well-pneumatized middle ear and mastoid; only 8.16% patients in the TFM group and 5.56% patients in the PFM group revealed a few soft tissue shadow (P = .89) between 2 groups. Fortunately, middle ear cholesteatoma was excluded by MRI. The findings demonstrated that no trimming margins induced long-term iatrogenic cholesteatoma. The possible reason was as follows: although the margin tissue was not artificially trimmed, the muco-epithelial junction and adhesive epithelium could also be mechanically trimmed by the graft placement. In addition, the cartilage graft was shaped 1 to 2 mm more than the perforation margins in the PFM group, which was similar to the size of perforation margins trimming by traditional myringoplasty.5,19 The medial cartilage graft prevented the epithelium from migrating inward. The cartilage is dense fibrous connective tissue and very hard; it is almost impossible for the epithelium to penetrate the cartilage. Thus, theoretically, cartilage underlay myringoplasty with PFMs is not sufficient to induce iatrogenic cholesteatoma. Some studies suggested that the development of cholesteatoma is related to the moist environment of the tympanic cavity and the long-term Eustachian tube dysfunction.20,21 The optimal time points for follow-up to monitor the development of cholesteatoma are unclear. Nejadkazem et al 10 suggested imaging examinations at 2 years after tympanoplasty, whereas Kawano 11 suggested them within 1 year. In addition, Gülşen and Erden 22 believed that follow-up for 6 months postoperatively is sufficient following cartilage graft application. Based on these authors’ findings, follow-up imaging examinations at 3 years were sufficient and reasonable for assessing the development of cholesteatoma.
Usually, the hearing improvement depends mainly on the integrity and motility of the TM and ossicular chain. Patients with ossicular chain abnormality were excluded in this study. There was significant hearing improvement before and after surgery in both groups. In addition, although no significant difference was found in hearing improvement between 2 groups, the PFM group showed better hearing restoration compared with the TFM group. The possible reason may be that the ossicular chain has been minimally damaged during the process of trimming margins.6,7 Another surprising finding is that, although no significant difference was found in hearing improvement at postoperative 3 months and 3 years, postoperative 3 years showed better hearing restoration in any group. These results agreed with other scholars’ findings.23,24 Kaya et al 24 believed that long-term hearing results of cartilage tympanoplasty seem to be better than short-term hearing results. The possible reason was that biological materials were completely absorbed in the tympanic cavity over time and the cartilage graft continued to thin.
Morphologically, 11.11% patients showed graft stratification in the PFM group; nevertheless, graft stratification did not affect perforation closure and hearing improvement. The mechanism of grafting stratification was unclear. We speculate that the fibrous layer of the TM remnant was not proliferated along the graft because of scar hyperplasia of perforation margins, but graft epithelization could be completed. The advantages of this study were endoscopic imaging, audiological data, and imaging examinations at postoperative 3-year follow-ups. The limitation of this study was small sample size and single-institution study. In addition, although patients were followed for 3 years, the long-term follow-up of 5–10 years should be encouraged to explore the development of cholesteatoma. Also, this study was only limited to underlay techniques; it is unclear whether preserving the perforation margins is suitable for other graft techniques. Therefore, further study should be considered in future.
Conclusions
The long-term graft success rate and hearing improvement of cartilage underlay myringoplasty with PFMs are reliable for repairing large perforations; 3-year imaging examinations did not reveal iatrogenic cholesteatoma. However, it may cause graft stratification and graft separation.
Footnotes
Authors’ contributions
Xuefei Ye: Analysis of data for the work, drafting the work, agreement to be accountable for all aspects of the work; final approval of the version to be published. Xiaoqiong Wang and Ruoqi Li: Analysis of data for the work, drafting the work, agreement to be accountable for all aspects of the work, and final approval of the version to be published. Xuejun Liu: Interpretation of data for the work, design of the work, final approval of the version to be published.
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was supported by Wenzhou Municipal Science and Technology Bureau, China (Grants Y20240326), Zhejiang Provincial Clinical Research Center for Pediatric Diseases, China (Grants ZJEK2310Y).
Ethics Approval and Consent to Participate
The study protocol was reviewed and approved by the Institutional Ethical Review Board of Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Zhejiang, China. Informed consent was obtained from all participant’s parents.
Consent for Publication
Written informed consent was obtained from all patients for publication of this study and any accompanying images.
Availability of Data and Materials
The datasets supporting the conclusions of this article are included within the article.
